Alarm motor



I 1,606,262 G. I. ROCKWOOD APARM MOTOR Filed Spt. 27, 1923 IIIIIIII/I Nov 9 1926 III Patented ev. 9,

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ra Z5 earner ALARM Moron.

Application filed. September 27,1923. Serial No. 665,213.

This invention relates to a water motor for operating an alarm adapted for general purposes. The invention is particularly adapted for use in connection with a water Wheel acted upon by a jet of water discharged when the main valve of an automatic fire alarm system is open. As ordinarily constructed this wheel is located in a casing which has a large outlet at the bottom. The wheel is designed to operate by the force of the water applied to the vanes thereof. The water is discharged under pressure against these vanes, or buckets, and it has been found that if the shape of the buckets is that best adapted to give the greatest-power and speed to the wheel shaft with a given nozzle and a high water pressure, not only is the rate of striking the motor gong too rapid for the most effective alarm (the vibrations of the bell being somewhat smothered by a too rapid series of blows thereon) but there occurs a very rapid rate of destruction of the striker and of the portion of the gong struck. Nevertheless, it is desirable to employ an eflicientand powerful wheel in order to ensure that it will operate at all, after a prolonged period of rest, on account of the likelihood of some corrosion setting in at the wheel shaft bearings, as such motor gongs may be at rest for years before a fire calls them automatically into action. Heretofore it hasbeen thought best to use an excess of power at the wheel so as to be sure to have enough to start the alarm if corroded.

The principal object of this invention is to avoid these difficulties in a very simple and inexpensive way.

Reference is to be had ing drawings, in which Fig. l is a central longitudinal sectional view of an alarm motor and connected parts constructed in accordance with this invention; and

to the accompany- Fig. 2 is a sectional view on the line 2--2 of Fig. 1.

This motor is constructed in the usual way, comprising a casing of semicircular shape at the top and gradually tapering down at the bottom to a large outlet opening 11. A nozzle 12 receiving water through pipe 13, discharges a jet of water into the interior of the casing on a line tangent to the rotary water motor wheel 15 located therein, causing it to turn freely on its shaft 16, centrally located in the cas- .dition for a short space of time only, after ing. This shaftv 16 passes through a support or wall 1'? and has on its end a rotar clapper 18 operating on a 19 oron any "other means for creating an audible alarm. The parts so far described are all old and subject to the above named objections The ou iet l1, as orc inarily designed, .is large enough to permit the casing to drain freely by gravity without filling. Therefore a strong jet of water striking on anefiicient form of wheel bucket can operate whe motor with great speed and suddenness H and even overcome extra friction caused by corrosion.

My invention consists in providing means for maintaining this desirable initial conwhich the discharge water, by backing up on the buckets of the running wheel, causes its rate of rotation to slow down considerably as a result of such contact. I have found that the resulting sequence of blows struck by the gong striker, being slower, gives a better vibration of the gong and an effective alarm, and, at the same time, so diminishes the force of each blow as to add greatly to the useful life of the appliance.v

.These means consist in providing a casing 10 having its lower portion somewhat enlarged over the size and shape required merely to drain away the water effectively, and in addition I plug up the opening 11 with a plug provided with a restricted drain outlet 21, preferably of non-corrodible metal. v

This drain outlet is designed to be too small to discharge the water admitted through the nozzle 12 if under high pressure until a suiiicient discharge water head has accumulated to cause. the casingto fill.

part way up and thus create a back pressure or drag of the discharged water on the backs of the wheel buckets. The size of the en largedportion of the casing and the diameter, of the hole in the plug are so designed and selected as to cause a short period of time to elapse before the water rises in the casing high enough to be engaged by the vanes of the motor. "This permits of the shaft being rotated at high speed and efficiency for a period of time to overcome the efiects of corrosion at the bearings and then the motor continues to operate, but ata materially lower speed.

Although I have illustrated and described a particular type of motor and alarm gong, I amv aware of the fact that the invention can be applied to alarm systems in general. I am also aware of the tact that modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the details of vonstruction'or the particular old elements to which it is shown as applied, but what I do claim is 1. The combination with a water Wheel and an alarm operated thereby of means for directing a jet of water against the wheel to rotate it at high speed at first, and means for causing the water to back up against the wheel after it has operated at full speed and slow it down while the jet operates at full speed.

2. In an alarm operating device, the combination with a casing, 21 Water wheel therein, and means for directing a jet of Water into said casing and into contact with the upper part of the wheel to rotate it, of means for leading the waste water from the casing in such proportions relative to the rate of entrance that the wheel will rotate at full speed at first and then be slowed up solely by Contact with water rising in the casing and will continue to rotate at slow speed.

In testimony whereof I have hereunto aiiixed my signature.

GEORGE I. ROCKVOOD. 

